Level-determining adhesive patch

ABSTRACT

An adhesive patch containing an integral spirit level, said adhesive patch comprising: a) a first transparent film comprising an indented region; b) a second film, having an upper surface that is attached to the lower surface of said first transparent film, such that the indented region of said first film and the portion of said second film that lies immediately below said indented region together define a closed tubular structure; c) level-indicating means associated with said tubular structure; and d) adhesive means for affixing the patch to a surface whose orientation is to be determined; wherein the level-indicating means provide an indication of the spatial orientation of the surface to which said adhesive patch is affixed.

FIELD OF THE INVENTION

The present invention relates to a level-determining device. Morespecifically, the present invention relates to an adhesive patchcontaining an integral spirit level.

BACKGROUND OF THE INVENTION

The use of spirit levels and other related leveling devices (such asclinometers) in a variety of engineering and domestic settings is wellknown in the art. In its most usual form, the spirit level consists of arigid-walled, transparent capsule partially filled with a liquid, intowhich is entrapped a bubble. By means of suitable markings placed eitheron the capsule itself or on a base member supporting said capsule, theuser is able to determine when the device is placed in a levelorientation in relation to a desired plane.

Most prior-art spirit levels are constructed using fluid-filled sealedglass or machined plastic capsules mounted on a rigid supporting member.One consequence of this traditional design is that the devices aredelicate, expensive to construct and bulky. Moreover, many such devicesneed to be hand-held while in use, thus rendering them unsuitable forapplications requiring indwelling spirit levels.

A need exists for an accurate, inexpensive spirit level of simpleconstruction that may be readily secured to a surface.

A partial solution to this problem was presented in U.S. Pat. No.4,100,681 which discloses a picture-leveling device in the form of atransparent tape having partially fluid filled blister-like cavities.The underside of this device is fitted with an adhesive tape to permitsaid device to be attached to the surface of a picture frame, whoselevel is to be checked. One significant drawback to this prior artsolution is the limited accuracy of the device. Furthermore, the fluidbubble is difficult to read and very hard to manufacture as the airbubble may vary in size during mass-production.

The aim of the present invention, which will shortly be disclosed anddescribed hereinbelow, is to provide an inexpensive level-determiningdevice that is equipped with adhesive means for applying said device tothe surface whose level is to be checked.

A further aim of the present invention is to provide an adhesive spiritlevel which may be used to accurately determine the spatial orientationof any plane of an object.

Yet another aim of the present invention is to provide an adhesivespirit level device that overcomes the disadvantages of prior artdevices.

Further advantages and objectives of the present invention will becomeclear as the description proceeds.

SUMMARY OF THE INVENTION

It has now been unexpectedly found that it is possible to construct anadhesive patch into which has been incorporated a low-profile spiritlevel of tubular design. The ease of construction and range of polymericand metallic materials that may be used makes it possible to produce alarge range of different shaped adhesive spirit level devices suitablefor a variety of applications, on an industrial scale.

The term “spirit level” as used hereinabove and hereinbelow is used toindicate any suitable device that may be used for determining whether asurface upon which said device rests, or to which said device isaffixed, is level. Despite the fact that the “spirit levels” of thepresent invention are not limited to devices containing “spirit”, (forexample, alcohols or alcohol mixtures such as used in most earlierdevices that are described by this term), this term is retained forreasons of convention and convenience of description, and is to beunderstood as being interchangeable with the term “level-determiningdevice”.

The present invention is primarily directed to an adhesive patchcontaining an integral spirit level, said adhesive patch comprising:

-   -   a) a first transparent film comprising an indented region;    -   b) a second film, having an upper surface that is attached to        the lower surface of said first transparent film, such that the        indented region of said first film and the portion of said        second film that lies immediately below said indented region        together define a closed tubular structure;    -   c) level-indicating means associated with said tubular        structure; and    -   d) adhesive means for affixing the patch to a surface whose        orientation is to be determined;    -   wherein the level-indicating means provide an indication of the        spatial orientation of the surface to which said adhesive patch        is affixed.

In a particularly preferred embodiment of the invention, theaforementioned level-indicating means comprises:

-   -   i) pre-calibrated markings located either on the closed tubular        structure or on the upper surface of the first transparent film        alongside said tubular structure; and    -   ii) at least one visible indicator located within said closed        tubular structure, wherein said visible indicator is either a        sphere or is chosen from the group consisting of gas-liquid        interface, liquid-liquid interface and gas-gas interface,    -   such that rotation of the surface to which said adhesive patch        is affixed causes relative movement of said visible indicator(s)        and said pre-calibrated markings.

All the above and other characteristics and advantages of the presentinvention will be further understood from the following illustrative andnon-limitative examples of preferred embodiments thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts one general embodiment of the device of the invention. Inthe version of the embodiment shown in FIGS. 1A and 1B, the adhesivesurface is attached to the left side of the patch, whiles FIGS. 1C and1D depict a different version having the adhesive surface adjoining theinferior side of the patch. FIGS. 1A and 1C show the patch in ahorizontal orientation, while FIGS. 1B and 1C illustrate the effect ofrotating said patch by 20 degrees. The location of the adhesive means isindicated by hatching.

FIG. 2 illustrates another embodiment of the device of the invention,wherein the tubular structure is curved and the level-indicating meansis provided by a sphere that may move freely within the fluid contents(or partial vacuum) present in said tubular structure. Various versionsof this embodiment, wherein the tubular structure contains a gas (or ispartially evacuated), a liquid or combination of liquid and gas, aredepicted in FIGS. 2A, 2B and 2C, respectively. While the sphere shown ineach of these figures is denser than the fluid contained within thetubular structure, FIG. 2D shows a version of this embodiment, whereinthe sphere is less dense than said fluid.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The device of the present invention may be conveniently manufactured inseveral different embodiments and conformations. Thus, with respect tothe spirit level element, the closed tubular structure may beconstructed in any convenient shape. In one preferred embodiment, forexample, the tubular structure is linear in shape. In another preferredembodiment, said tube is provided in an annular form. In yet furtherpreferred embodiments, the tube may be either curved or U-shaped. Inother embodiments, the tubular structure may also contain expanded ornarrowed sections at various points along its length.

The level-indicating means of the presently claimed device may be ofseveral different types, employing a variety of physical principles. Inone embodiment, the level-indicating means comprises markings placed onor adjacent to two regions of the closed tubular structure, saidstructure being partially filled with a fluid. The fluid that iscontained within the tubular structure may be either a gas (such as air,oxygen, nitrogen, helium etc.) or a liquid (such as water, coloredwater, colored emulsions, phosphorescent solutions, fluorescentsolutions, alcohols such as methanol, ethanol or propanol, organiccompounds such as turpentine, petrol, oil, polar liquids, phenols,non-polar liquids, liquids containing detergents or other surfactants orlight reflective liquids). In one particularly preferred embodiment (asdepicted in FIG. 1) the tubular structure is annular in shape, and ispartially filled with a colored liquid. The rest of the internal volumeof said structure contains air that was trapped inside the tube duringthe process of manufacture (as will be described hereinbelow). Inaddition, left- and right-side calibrated markings are formed on theupper surface of the first film, adjacent to said tubular structure,said markings being arranged such that when the device is in a levelorientation, the two liquid-air interfaces are located opposite theleft- and right-side zero markings. When the device is rotated, theliquid remains essentially stationary in relation to an imaginaryhorizontal plane, due to the equal pressures exerted by the entrappedair on each of the air-liquid interfaces. However, due to the rotationof the tubular structure and its associated calibrated markings, theaforementioned liquid-air interfaces will now be situated alongsidedifferent calibrated markings (i.e., not alongside the zero markings).In a particularly preferred embodiment (as shown in FIG. 1) the markingsare pre-calibrated in order to provide an indication of the anglethrough which the device of the invention has been rotated.

In a further preferred embodiment, the closed tubular structure containsair, and the level-indicating means comprise (in addition to thepre-calibrated markings) by a drop of liquid (e.g. colored water oralcohol) that is free to move within said air in response to rotationaldisplacement of the device, the orientation of said device beingindicated by markings present on or alongside said tubular structure.

In a further preferred embodiment of the device of the invention, theclosed tubular structure is partially filled with a colored liquid, thelevel indicating means being represented by a second liquid that fillsall or most of the remaining space within the tube, said second liquidbeing of a different color from the first liquid and also beingimmiscible therewith. Upon rotation of the device, the markings made onor alongside the closed tubular structure rotate relative to theliquid-liquid interface(s). As mentioned hereinabove, any twodifferently-colored and mutually immiscible liquids may be used,including (but not limited to) water, colored water, colored emulsions,phosphorescent solutions, fluorescent solutions, alcohols such asmethanol, ethanol or propanol, organic compounds such as turpentine,petrol, oil, polar liquids, phenols, non-polar liquids, liquidscontaining detergents or other surfactants and light reflective liquids.

In yet a further preferred embodiment, the level-indicating means areprovided by a sphere (such as a ball bearing) that is capable ofmovement along the tubular structure, said structure being filled witheither a dense liquid or a dense gas, such as air, said sphere beingeither less dense or denser than said liquid or said gas. In thoseembodiments that utilize spheres as part of the level-indicating means,the closed tubular structure is required to be either circular, U-shapedor otherwise curved in shape. Preferably, the sphere is slightly smallerin diameter than the internal diameter of the tube, such that the linearmovement of said sphere is unhindered by either frictional resistanceimposed by the internal walls of said tube or by non-axial reflection ofthe sphere off said internal walls. The sphere may be constructed of anysuitable material including, but not limited to, iron, steel, porcelain,glass, synthetic polymers and ceramic materials. FIG. 2 pictoriallyrepresents several different versions of this embodiment of theinvention. Thus, FIG. 2A depicts a device according to the presentinvention comprising a curved tubular structure containing a sphere, asdescribed hereinabove. In this particular embodiment, the remaininginternal space of said curved tubular structure is either filled with agas such as air, or contains a partial vacuum. In the embodiment shownin FIG. 2B, the curved tubular structure contains, in addition to thesphere, a liquid, such as air or an alcohol (indicated by shading). FIG.2C depicts a similar embodiment to that shown in FIG. 2B, with theexception that the tubular structure contains a gas, such as air or acomponent thereof, in addition to the sphere and the liquid. In all ofthe embodiments depicted in FIGS. 2A-2C, the sphere is denser than thefluid(s) that fill the remaining internal space within the curved tube.In contradistinction, FIG. 2D depicts an embodiment wherein the sphereis less dense than the fluid contents of the curved tube.

In most embodiments of the invention, the closed tubular structure willhave markings on or alongside its surface to indicate the desired(generally, horizontal) position. In other embodiments, said markingswill be placed such that they provide an indication of when the deviceof the invention is placed in an exactly vertical orientation. In aparticularly preferred embodiment, further, pre-calibrated angularmarkings indicating the degree of rotation will also be presentalongside or on the surface of the closed tubular structure.

In one preferred embodiment of the invention, the first film isconstructed of a transparent, synthetic polymer. Although any suchsuitable polymer may be used to construct the first film, particularlypreferred materials include polypropylene, polyethylene, polyester,polyteraphtalate, polycarbonate, polyvinyl chloride and combinations ofsaid materials, either as mixtures or as distinct bilayered ormultilayered structures.

The purpose of the second film is to provide the posterior wall of thetube, and further to permit affixation of the device of the inventiononto a surface of the object whose level is to be checked. In onepreferred embodiment, the second film may be constructed of atransparent polymer similar to the abovementioned examples of materialsused in the construction of the first film. In another preferredembodiment, the second film may comprise an opaque material in order toprovide better contrast between the liquid height and thelevel-determining markings of the device. In this case the second filmmay be a metal film or a multilayered film of metal and plastic.

Either the first film or the second film or, alternatively, both films,may be coated with an adhesive to promote bonding between the two films.

Use of the Device

Typically, the device of the invention is used to determine whether apicture-frame has been hung in a level manner, that is, with the topsurface of said frame in a plane approximately parallel to the floorand/or ceiling. In such a case, the device may be affixed to the frontsurface of the frame such that the essentially horizontal edges of saiddevice are parallel to the essentially horizontal upper and/or loweredge of said frame, the adhesive portion thereof being pressed firmlyonto the frame in order to ensure that the device is immobilized inrelation to the picture-frame. Alternatively, the device of theinvention may be affixed to the upper surface of the picture-frame in asimilar way.

As mentioned hereinabove, the first film may be equipped withpre-calibrated markings on its upper surface, the purpose of which is toprovide a quantitative measure of the degree of tilt of a non-levelobject. The use of such a calibrated device is illustrated in FIG. 1.Thus, if a device according to the present invention is adhered to anobject placed in a horizontal position (FIGS. 1A and 1C), the upperlevels of the fluid contained within the annular tube depicted thereincoincides with the zero markings that are located on the upper surfaceof the first film. When the device is tilted by 20 degrees in aclockwise direction, the upper levels of the fluid then becomecoincident with the 20 degree markings (FIG. 1B). FIG. 1D similarlyillustrates the situation wherein the device is rotated by 20 degrees inan anti-clockwise direction.

Finally, it should be noted that the device of the invention is notlimited in its applicability to picture-hanging. Rather, it may be usedin any circumstance in which the spatial orientation of an article orobject is required to be determined. Many such applications are to befound in the building trades including, for example, the erection ofpre-constructed (e.g. plasterboard) walls.

Manufacture of the Device

One embodiment of the device of the present invention may beconveniently manufactured in the following manner:

1. An indent of the desired shape (e.g. annular, U-shaped, linear etc.)is formed in an optically clear film such as polyester having athickness of about 50-250 micrometer. Such indents may be formed by anysuitable means, but are preferably created by use of a vacuum-formingtechnique, or by placing the film over a solid former of the desiredshape, heating the film to about 180° C. and applying pressure to thefilm in order to create the negative counterpart of said solid former onthe film. Any other suitable die-forming or pressure-forming techniqueemploying suitable mandrels or coining or embossing tools may also beused.

2. The first film containing the indented structure is placedhorizontally and the indent is then partially filled with a spirit orsuitable solution, including (but not restricted to) water, coloredwater, colored emulsions, phosphorescent solutions, fluorescentsolutions, alcohols such as methanol, ethanol or propanol, organiccompounds such as turpentine, petrol, oil, polar liquids, phenols,non-polar liquids, liquids containing detergents or other surfactantsand light reflective liquids.

3. A second (polymeric or metallic) film is then heat laminated oradhered to the indented clear film thus locking in the solution.Suitable level markings are then added to the upper surface of the firstfilm.

4. Pressure-sensitive adhesive is applied to the under-surface of thesecond film, either to across the entire area of said second film, or toselected regions thereof. Optionally, suitable folding lines may becreated on the second film, such that an adhesive-coated portion of thedevice of the invention may be folded in order that said portion becomesorientated at angle (preferably, but not limited to, 90 degrees) to thelevel-determining structure. Such an embodiment is useful incircumstances wherein there is a need to avoid contacting a decorativesurface, for example a painting or decorative frame thereof, withadhesive. In such a case, the adhesive-coated portion of the device maybe affixed to the upper surface of the picture frame, and the devicefolded at the desired angle (usually, but not limited to, 90 degrees)such that the level-determining structure may be read from the front ofthe painting.

5. Markings representing the level position and various pre-determinedrotational angles therefrom are made either on the surface of thetubular structure, or alongside said tubular structure on the uppersurface of the first transparent film. These markings may be made by anysuitable technique known in the art, including (but not limited to)engraving, etching, and application of black, colored or fluorescenttransfers.

In a modification of the above-described procedure, one may completelyfill the indent described above with two immiscible liquids of similaror different colors.

In the case of yet another preferred embodiment of the invention, asphere may be placed inside the indented portion of the first filmdescribed in step 1, above. At the same time as the sphere is placedinside said indented portion, a liquid or combination of liquid and gasmay also be inserted therein.

While specific embodiments of the invention have been described for thepurpose of illustration, it will be understood that the invention may becarried out in practice by skilled persons with many modifications,variations and adaptations, without departing from its spirit orexceeding the scope of the claims.

1. An adhesive patch containing an integral spirit level, said adhesivepatch comprising: a) a first transparent film comprising an indentedregion; b) a second film, having an upper surface that is attached tothe lower surface of said first transparent film, such that the indentedregion of said first film and the portion of said second film that liesimmediately below said indented region together define a closed tubularstructure; c) level-indicating means associated with said tubularstructure; and d) adhesive means for affixing the patch to a surfacewhose orientation is to be determined; wherein the level-indicatingmeans provide an indication of the spatial orientation of the surface towhich said adhesive patch is affixed.
 2. The adhesive patch according toclaim 1, wherein the level-indicating means comprises: i) pre-calibratedmarkings located either on the closed tubular structure or on the uppersurface of the first transparent film alongside said tubular structure;and ii) at least one visible indicator located within said closedtubular structure, wherein said visible indicator is either a sphere oris chosen from the group consisting of gas-liquid interface,liquid-liquid interface and gas-gas interface, wherein rotation of thesurface to which said adhesive patch is affixed causes relative movementof said visible indicator(s) and said calibrated markings.
 3. Theadhesive patch according to claim 2, wherein the closed tubularstructure is provided in an annular shape.
 4. The adhesive patchaccording to claim 3, wherein the annular closed tubular structure ispartially filled with a colored liquid, and wherein the visibleindicators are provided by the two air-colored liquid interfaces presentwithin said closed tubular structure, such that upon rotation of saidpatch, the pre-calibrated markings move relative to said interfaces. 5.The adhesive patch according to claim 4, wherein the colored liquidcomprises a fluorescent material.
 6. The adhesive patch according toclaim 4, wherein the liquid comprises a light-reflective material. 7.The adhesive patch according to claim 2, wherein the closed tubularstructure is provided in a curved shape.
 8. The adhesive patch accordingto claim 7, wherein the curved tubular structure contains either aliquid or a liquid and a gas, and wherein the visible indicator isprovided by a sphere, such that upon rotation of said patch, thepre-calibrated markings move relative to said sphere.
 9. The adhesivepatch according to claim 2, wherein the closed tubular structure isessentially straight.
 10. The adhesive patch according to claim 1,wherein the pre-calibrated markings are fluorescent markings.